Desk lamp



FIG. 1 shows a perspective view of a design for a desk lamp.

FIG. 2 shows a left side view of the design. A right side view of the design is a mirror image of the left side view.

FIG. 3 shows a top view of the design.

FIG. 4 shows a bottom view of the design; and,

FIG. 5 shows a front view of the design.

The broken-line features in the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a desk lamp, as shown and described. 